Measurements to parameterizations: mixing in the open and coastal oceans

参数化测量：公海和沿海海洋的混合

• 批准号: RGPIN-2017-04050
• 负责人: Klymak, Jody
• 金额: $ 1.97万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681896
• 关键词: Measurements; parameterizations; mixing; open; coastal

Ocean mixing is a crucial component of the earth system, driving heat downwards, mixing nutrients upwards, and energizing ocean circulations from coastal to global scales. Quantifying, characterizing, and predicting ocean mixing is a daunting task given the spread of spatial and temporal scales that must be resolved. Our group makes innovative measurements of ocean mixing and develops simplified ocean-physics simulations that elucidate the mixing mechanisms. The combination of observations and simulation in one group is rare internationally.******We propose to focus on four mixing processes. The first is to measure lateral stirring processes in the North East Pacific using our undulating Moving Vessel Profile and a ship's current profiler. As numerical models start to resolve mesoscale eddies we need new parameterizations of submesoscale processes to make sure these models mix eddy-borne heat and nutrients properly in the upper ocean. The NE Pacific is a good laboratory to measure these processes, as the warm California Undercurrent mixes laterally with the cold Alaskan gyre. Our measurements will help set the baseline for future parameterization of this mixing in models being developed by Bedford Institute of Oceanography.******The second process is mixing at abrupt topography. We have developed a parameterization for tidally generated turbulence over isolated bathymetry. However, before this work is useful for large-scale simulations, we must extend its use to more complicated bathymetry. This will involve new simulations in both two and three dimensions, and will make exciting student theses.******The third process is to numerically confine a tidal energy budget in Knight Inlet, a coastal fjord. Tidal energy budgets over isolated topography like the sill in Knight Inlet or Hawaii indicate that much of the energy lost from the surface tide radiates away as internal tides. No one has closed a credible budget indicating where that energy eventually dissipates. We propose to do this for a high-resolution simulation of Knight Inlet simply because it is well-confined, and I hope that we can verify the mechanisms in future field programs.******Finally, I propose to carry on the work of graduate student Ken Hughes, examining the role of mixing and hydraulic flows in controlling the flow of fresh Arctic Ocean water through the Canadian Arctic Archipelago and into the North Atlantic. Recent large-scale models overestimate the transport of these flows by up to 80%, indicating missing physics in those models. We will carry out high-resolution nested simulations of the flow through these channels, including the effect of ice, and working with large-scale modellers to parameterize the form drag due and mixing on the flow due to underresolved hydraulic flows.******While many of these problems are local to Canada, they all have relevance to better understanding globally important mixing processes.

海洋混合是地球系统的重要组成部分，它向下推动热量，向上混合营养物质，并为从沿海到全球范围的海洋环流注入活力。考虑到必须解决的空间和时间尺度的扩展，量化、表征和预测海洋混合是一项艰巨的任务。我们的小组对海洋混合进行创新测量，并开发简化的海洋物理模拟来阐明混合机制。将观测和模拟结合在一组中在国际上是罕见的。******我们建议重点关注四个混合过程。第一个是使用我们起伏的移动船舶剖面和船舶的电流剖面仪来测量东北太平洋的横向搅拌过程。随着数值模型开始解决中尺度涡流问题，我们需要对亚中尺度过程进行新的参数化，以确保这些模型在上层海洋中正确混合涡流产生的热量和营养物质。东北太平洋是测量这些过程的良好实验室，因为温暖的加利福尼亚暗流与寒冷的阿拉斯加环流横向混合。我们的测量将有助于为贝德福德海洋研究所正在开发的模型中的这种混合的未来参数化设定基线。******第二个过程是在突变地形下进行混合。我们开发了一种针对孤立测深中潮汐产生的湍流的参数化方法。然而，在这项工作可用于大规模模拟之前，我们必须将其用途扩展到更复杂的测深。这将涉及二维和三维的新模拟，并将撰写令人兴奋的学生论文。******第三个过程是在数值上限制沿海峡湾奈特湾的潮汐能预算。奈特湾或夏威夷等孤立地形上的潮汐能收支表明，表面潮汐损失的大部分能量以内潮汐的形式辐射出去。没有人完成一份可靠的预算来表明这些能量最终消散在哪里。我们建议对 Knight Inlet 进行高分辨率模拟，只是因为它具有良好的约束性，我希望我们能够在未来的现场项目中验证该机制。 *****最后，我建议继续研究生肯·休斯 (Ken Hughes) 的工作，研究了混合和水力流在控制北冰洋淡水流经加拿大北极群岛进入北大西洋方面的作用。最近的大型模型高估了这些流的传输高达 80%，这表明这些模型中缺少物理现象。我们将对通过这些通道的流动进行高分辨率嵌套模拟，包括冰的影响，并与大型建模者合作，参数化由于解析不足的水力流而导致的形状阻力和流动混合。**** **虽然其中许多问题都是加拿大本地问题，但它们都与更好地了解全球重要的混合过程相关。